The invention relates in general to antennas and more specifically to an apparatus and method for adjusting antenna characteristics using tunable parasitic elements.
Electromagnetic signals are transmitted and received through antennas. The selection or design of an antenna for a particular device may depend on a variety of factors including signal frequencies, antenna performance, and available space. In conventional antenna systems, an antenna is selected and optimized to account for a wide variety of possible situations. Conventional techniques may utilize parasitic elements, sometimes referred to as “brackets”, to manipulate antenna characteristics. The selection and adjustment is often a compromise to minimize the susceptibility to anticipated situations such as changes in signal strength, operating frequencies, interference, antenna radiation patterns, and the effects of objects and user body parts when positioned near the device. As a result, maximum performance is rarely achieved for any particular situation.
Accordingly, there is need for an apparatus and method for adjusting antenna characteristics using tunable parasitic elements.